1. Field of the Invention
The present invention relates to microcapsules for the immunological determination of trace amounts of biochemical components utilizing immunological reaction which comprise a core material and a wall material having an antigen or antibody bound thereto on the surface thereof.
The present invention also relates to a process for the determination of such biochemical components using such microcapsules.
2. Brief Description of the Prior Art
Various methods have been proposed for the immunological determination of biochemical components having immunological activity. For example, one known method relates to determining biochemical components by observing agglutination between test samples and antigen- or antibody-coupled animal blood red cell (also referred to as erythrocyte), a high molecular weight latex, high molecular weight polymer particles, etc., on a microplate or the like. In recent years, the art has also directed substantial attention to radioimmunoassay and enzyme immunoassay.
In the prior art methods, while sheep blood red cell is most commonly used as a carrier particle for binding an antigen or antibody used in the agglutination of an antigen-antibody reaction, organic or inorganic particles such as a polystyrene latex, a polyester, a nylon, kaolin, etc., have also been employed. In the case of using such carrier particles, blood red cells have been coupled with an antigen or antibody using an aldehyde such as glutaraldehyde, etc., while a polystyrene latex, a polyester, a nylon, kaolin, etc., have been physically bound thereto utilizing physical adsorption.
However, in the case of using sheep red cells as carrier particles, quality was uneven and the antigen-antibody reaction has been interpreted only with poor accuracy since these carrier particles originate from a living body. Furthermore, non-specific reactions tend to occur since the sheep red cell carrier inherently has antigens and antibodies, reproducibility of the antigen-antibody reaction is poor and cost is high, all of which are disadvantages in using sheep red cells as carrier particles.
On the other hand, systems using a polystyrene latex, a polyester, a nylon, inorganic particles or the like encounter other shortcomings, e.g., in addition to high cost, immobilization is weak due to physical adsorption of the antigen or antibody to the carrier particles and, as a result, an antigen or antibody is not easy to isolate, sensitivity of the antigen-antibody reaction is reduced and reproducibility of the antigen-antibody reaction is inferior. These disadvantages increase dramatically when the analytical system is stored for a long period of time.